This invention relates to a method for constructing a spherical dome, and more particularly to a dome constructing method which is enabled to construct a spherical dome, if relatively high, merely by using a relatively small-sized construction equipment and by assembling it at a relatively low position.
When a large-sized spherical dome is to be constructed, there may be adopted a method of constructing a polyhedron for a skeleton at first. For constructing this polyhedral skeleton, it is a general method of the prior art to construct a foundation on the land to be scheduled so that the polyhedron for the skeleton is sequentially assembled up on the foundation. As the spherical dome grows the larger (to have the highest point up to several tens meters in recent years), therefore, not only the construction equipment used for the dome construction becomes the larger but also the special works are required at the higher position.
When the works at the high position are increased in the spherical dome constructing method of the prior art, more specifically, large-sized construction equipments are required for building up the scaffold and for lifting and assembling the materials. On the other hand, special considerations have to be taken into the safety management of the workers at the high position. For this dome construction, great quantities and numbers of materials, labors and expenses are required to raise various problems in the drop of efficiency, in the rise of the construction cost and so on.
In order that the workers may go up to the their positions, for example, it is indispensable to construct a long scaffold, and it takes a sequentially longer time to lift the materials to be assembled. Thus, the spherical dome constructing method of the prior art have difficult problems to solve.
This invention relates to a dome constructing method for constructing a spherical dome by assembling a polyhedral skeleton and then by finishing the interior/exterior of the same, as will be specified in the following. Specifically, a plurality of joints, which are to be arranged when assembled at the positions of the individual vertexes of a polyhedral skeleton and each of which has a plurality of joint blades in the directions of the individual sides of the polyhedral skeleton, as extended from said individual vertexes, and a plurality of frame members are adopted as members for constructing the polyhedral skeleton of the spherical dome. Three joints and three frame members are assembled into a triangular frame or a basic unit of the polyhedral skeleton in a grounded state by using the three joints as the vertexes and the three frame members as the individual sides of the triangular frame. In addition, a new triangular frame is assembled around said grounded triangular frame by using similar frame members and joints, thereby to assemble the polyhedral skeleton of a polyhedral cone such as a pentahedral cone or a hexahedral cone, which uses the joints positioned at one vertex of said grounded triangular frame as its vertex and said grounded triangular frame as its one side. When the polyhedral skeleton of a polyhedral cone is thus assembled, a triangular frame different from said triangular frame is newly grounded by turning said polyhedral skeleton. The polyhedral skeleton is subsequently assembled by repeating similar assembling works, wherein the assembled polyhedral skeleton is fixed on the foundation, and the fixed polyhedral skeleton is then finished on its interior/exterior to complete the spherical dome.
According to this invention, more specifically, there is proposed a dome constructing method for constructing a spherical dome by assembling a polyhedral skeleton and then by finishing the interior/exterior of the same, which method comprises the following steps, by using a plurality of joints, which are to be arranged when assembled at the positions of the individual vertexes of a polyhedral skeleton and each of which has a plurality of joint blades in the directions of the individual sides of the polyhedral skeleton, as extended from said individual vertexes, and a plurality of frame members are adopted as members for constructing the polyhedral skeleton of the spherical dome, of steps:
(1) assembling a first triangular frame having three frame members as its sides in a grounded state with a side formed of said first triangular frame being in parallel with the ground surface, by using three joints as vertexes and three frame members to connect the two end sides of the three frame members to the adjoining ones of a plurality of joint blades in said three joints;
(2) assembling a polyhedral cone skeleton of a polyhedron, which has said one joint as its vertex and the number of the joint blades of said one joint as its side number, and which contains a side formed of said first triangular frame as its one side by connecting one-end sides of the remaining individual frame members to at least one of the three joints and connecting the joint blades of the remaining joints to the other end sides of each of said remaining frame members;
(3) assembling a polyhedral cone skeleton, which has said one joint of said grounded triangular frame as its vertex and the number of the joint blades of said one joint as its side number and which contains the side formed of said grounded triangular frame as its one side, by turning the polyhedral cone skeleton assembled at said step (2), to ground a triangular frame other than said first triangular frame so that a side formed thereof may be in parallel with the ground surface, by connecting one-end sides of the remaining individual frame members to at least one of the three joints positioned at the vertexes of said grounded triangular frame, and by connecting the joint blades of the remaining joints to the other end sides of each of said remaining frame members;
(4) assembling a polyhedral cone skeleton which has said one joint of said newly grounded triangular frame as its vertex and the number of the joint blades of said one joint as its side number and which contains the side formed of said newly grounded triangular frame as its one side, by turning the polyhedral skeleton assembled at said step (3), by grounding the triangular frame other than the said first triangular frame and the triangular frame grounded at said step (2), so that the side formed thereof may be in parallel with the ground surface, by connecting one-end sides of said remaining frame members to the individual joint blades of at least one of the three joints positioned at the vertexes of said newly grounded triangular frame, and by connecting the joint blades of said remaining joints to the other end sides of said remaining individual frame members;
(5) assembling the skeleton of the polyhedron which has a plurality of joints as its individual vertexes and a plurality of frame members as its individual sides, by repeating said step (4); and
(6) completing the spherical dome by fixing the skeleton of the assembled polyhedron on the foundation and then by finishing the interior/exterior of the polyhedron.
In said method, the joint blades of the joint are four to six. If there are used a plurality of joints having four joint blades and a plurality of joints having six joint blades, for example, it is possible to construct a polyhedral skeleton having twenty four sides. If there are used joints (twelve) having five joint blades and joints (twenty) having six joint blades, it is possible to construct a polyhedral skeleton having sixty sides.
Here in said dome constructing method, after the polyhedral skeleton having a plurality of joints as its vertexes and a plurality of frame members as its sides was assembled, it can be placed in a hole, which has been excavated to have a depth of several underground floors in the scheduled land, and is fixed in the foundation. After this, the polyhedral skeleton can also be finished on its interior/exterior to complete the spherical dome.
After the polyhedral skeleton having a plurality of joints as its vertexes and a plurality of frame members as its sides was assembled, it is moved to the scheduled land, and reinforcing bars are laid over the grounded triangular frame. Concrete is placed over the reinforcing bars to construct the foundation of the dome. After this, the polyhedral skeleton can also be finished on its interior/exterior to complete the spherical dome.
According to the dome constructing method of this invention, the polyhedral skeleton for the spherical dome can be constructed at a relatively low position near the ground surface. It is sufficient to prepare the scaffold which has been used in the prior art for constructing an ordinary building having a two floors or the like. The works can be done at a relatively low position while retaining the safety of workers easily. On the other hand, the polyhedral skeleton for constructing the spherical dome is enabled to continue its assembling works by turning the polyhedral skeleton such as a pentahedral cone or a hexahedral cone, each time three joints and three frame members are used to assemble a triangular frame having the three joints as its vertexes and the three frame members as its sides sequentially thereby to assemble the polyhedral skeleton. If one set of movable scaffold is prepared, therefore, it is economically possible to move the scaffold for the continuous use.
According to the dome constructing method of this invention, all the polyhedral skeletons for the skeleton of the dome can be assembled at a position near the ground. For the dome construction, therefore, the large-sized construction equipments, as might otherwise be necessary in the prior art, can be eliminated, and a relatively low scaffold is sufficient. On the other hand, main works can be done at the low position so that the dome construction can be made highly efficiently in all the works including the lifting of the materials (e.g., the joints or the frame members) for constructing the polyhedral skeleton. Thus, it is possible to reduce the labors in the spherical dome construction thereby to shorten the construction period and lower the construction cost.
According to the dome constructing method of this invention, the fundamental unit of the polyhedral skeleton for the spherical dome construction is the triangular frame having the three joints as its vertexes and the three frame members as its individual sides. Therefore, the polyhedral skeleton is remarkably strong even in its partially completed state so that it is hardly deformed in its assembling procedure while hardly requiring a remedy of the shape of the polyhedral skeleton being assembled.
On the other hand, the polyhedral skeleton, as assembled for the dome construction, is the polyhedron having sixty sides and so on and is spherical so that it is balanced in the stress at the individual portions. Even if an external force is partially applied, it is rationally dispersed. Therefore, the stress is hardly concentrated locally to break the polyhedral skeleton.
The polyhedral skeleton to be formed by assembling the triangular frames of said basic unit sequentially is a quadrangular pyramid, a pentahedral cone or a hexahedral cone having the joints as its vertexes, as determined by the number of the joint blades belonging to the joints. The angles, at which the joint blades are attached to the joints, are determined by the directions of the individual sides of the polyhedron, as extending from the vertexes of the polyhedral skeleton using said joints.
These joints can be highly precisely manufactured by casting to the sizes which have been determined by the design. The joints can also be manufactured by welding the joint blades at predetermined angles to a cylindrical body.
On the other hand, the frame members to construct the individual sides of the triangular frame or said basic unit can be manufactured in advance to a high sizing precision because the sides of the polyhedral skeleton scheduled to construct the quadrangular pyramid, the pentahedral cone or the hexahedral cone have known lengths. These frame members are made of iron pipes, pipes or frames extrusion-molded of aluminum, or timber.
The joints of the frame members to the joint blades of the joint can be done merely by jointing the end portion sides of the frame members, which have been highly precisely made in advance, to the joint blades having a predetermined angle. Therefore, the joints can be done simply and extremely highly precisely not by the skilled workers.
Specifically, the construction of the polyhedral skeleton for the spherical dome construction in the dome constructing method of the present invention can be made extremely simply, highly precisely and efficiently not by the skilled workers so that the dome can be constructed simply, efficiently and highly precisely
Here, the connections of the frame member end portions to the joint blades of the joints can be made by means of bolts and nuts, or pins. In the fastening case using the bolts and nuts, no connection fault will occur if a torque wrench is used by checking its fastening force.